From 7ce79380d1c082fff51f8dd5f559fea97d20ff07 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Wed, 27 Mar 2013 10:25:10 +1100 Subject: [PATCH] dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present() Move the calls to memcpy_fromio() up into the loop in dmi_scan_machine(), and move the signature checks back down into dmi_decode(). We need to check at 16-byte intervals but keep a 32-byte buffer for an SMBIOS entry, so shift the buffer after each iteration. Merge smbios_present() into dmi_present(), so we look for an SMBIOS signature at the beginning of the given buffer and then for a DMI signature at an offset of 16 bytes. Signed-off-by: Ben Hutchings Reported-by: Tim McGrath Tested-by: Tim Mcgrath Cc: Zhenzhong Duan Signed-off-by: Andrew Morton --- drivers/firmware/dmi_scan.c | 80 +++++++++++++++++-------------------- 1 file changed, 37 insertions(+), 43 deletions(-) diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 4cd392dbf115..3439f59123ed 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -410,22 +410,45 @@ static void __init dmi_dump_ids(void) printk(KERN_CONT "\n"); } -static int __init dmi_present(const char __iomem *p) +static int __init dmi_present(const char *buf) { - u8 buf[15]; + int smbios_ver; - memcpy_fromio(buf, p, 15); - if (dmi_checksum(buf, 15)) { + if (memcmp(buf, "_SM_", 4) == 0 && + buf[5] < 32 && dmi_checksum(buf, buf[5])) { + smbios_ver = (buf[6] << 8) + buf[7]; + + /* Some BIOS report weird SMBIOS version, fix that up */ + switch (smbios_ver) { + case 0x021F: + case 0x0221: + pr_debug("SMBIOS version fixup(2.%d->2.%d)\n", + smbios_ver & 0xFF, 3); + smbios_ver = 0x0203; + break; + case 0x0233: + pr_debug("SMBIOS version fixup(2.%d->2.%d)\n", 51, 6); + smbios_ver = 0x0206; + break; + } + } else { + smbios_ver = 0; + } + + buf += 16; + + if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) { dmi_num = (buf[13] << 8) | buf[12]; dmi_len = (buf[7] << 8) | buf[6]; dmi_base = (buf[11] << 24) | (buf[10] << 16) | (buf[9] << 8) | buf[8]; if (dmi_walk_early(dmi_decode) == 0) { - if (dmi_ver) + if (smbios_ver) { + dmi_ver = smbios_ver; pr_info("SMBIOS %d.%d present.\n", dmi_ver >> 8, dmi_ver & 0xFF); - else { + } else { dmi_ver = (buf[14] & 0xF0) << 4 | (buf[14] & 0x0F); pr_info("Legacy DMI %d.%d present.\n", @@ -435,40 +458,14 @@ static int __init dmi_present(const char __iomem *p) return 0; } } - dmi_ver = 0; - return 1; -} -static int __init smbios_present(const char __iomem *p) -{ - u8 buf[32]; - - memcpy_fromio(buf, p, 32); - if ((buf[5] < 32) && dmi_checksum(buf, buf[5])) { - dmi_ver = (buf[6] << 8) + buf[7]; - - /* Some BIOS report weird SMBIOS version, fix that up */ - switch (dmi_ver) { - case 0x021F: - case 0x0221: - pr_debug("SMBIOS version fixup(2.%d->2.%d)\n", - dmi_ver & 0xFF, 3); - dmi_ver = 0x0203; - break; - case 0x0233: - pr_debug("SMBIOS version fixup(2.%d->2.%d)\n", 51, 6); - dmi_ver = 0x0206; - break; - } - return memcmp(p + 16, "_DMI_", 5) || dmi_present(p + 16); - } return 1; } void __init dmi_scan_machine(void) { char __iomem *p, *q; - int rc; + char buf[32]; if (efi_enabled(EFI_CONFIG_TABLES)) { if (efi.smbios == EFI_INVALID_TABLE_ADDR) @@ -481,10 +478,10 @@ void __init dmi_scan_machine(void) p = dmi_ioremap(efi.smbios, 32); if (p == NULL) goto error; - - rc = smbios_present(p); + memcpy_fromio(buf, p, 32); dmi_iounmap(p, 32); - if (!rc) { + + if (!dmi_present(buf)) { dmi_available = 1; goto out; } @@ -499,18 +496,15 @@ void __init dmi_scan_machine(void) if (p == NULL) goto error; + memset(buf, 0, 16); for (q = p; q < p + 0x10000; q += 16) { - if (memcmp(q, "_SM_", 4) == 0 && q - p <= 0xFFE0) - rc = smbios_present(q); - else if (memcmp(q, "_DMI_", 5) == 0) - rc = dmi_present(q); - else - continue; - if (!rc) { + memcpy_fromio(buf + 16, q, 16); + if (!dmi_present(buf)) { dmi_available = 1; dmi_iounmap(p, 0x10000); goto out; } + memcpy(buf, buf + 16, 16); } dmi_iounmap(p, 0x10000); } -- 2.39.5